/*linear：线性过渡 ease：平滑过渡 ease－in：由快到慢 ease－out：由快到慢 ease－in－out：由由慢到快再到慢*/
.linear{
    animation-timing-function: linear;
    -webkit-animation-timing-function: linear;
}
.ease{
    animation-timing-function:ease;
    -webkit-animation-timing-function:ease;
}
.ease-in{
    animation-timing-function:ease-in;
    -webkit-animation-timing-function:ease-in;
}
.ease-out{
    animation-timing-function:ease-out;
    -webkit-animation-timing-function:ease-out;
}
.ease-in-out{
    animation-timing-function:ease-in-out;
    -webkit-animation-timing-function:ease-in-out;
}